Free Flight: Duration
ONE OF THE SUREST WAYS to stir up a hornet's nest is to start talking about rules changes; one of the most regular stirrers is Aram Schlosberg. There has been a lot of discussion in the last few years about splitting the FAI events (FIA towline glider, F1B Wakefield rubber, and F1C power) into technical and nontechnical branches. This would allow those who wanted to opt out of the high-tech "horsepower" race to enjoy flying the events on a more relaxed level. It could be done by limiting wingspan (which reduces the structural advantage of composite materials) and by limiting the number of automated functions, such as bunt, auto stab, auto rudder, variable-pitch props, delayed prop release, etc. to reduce the complexity of the model. Aram's latest suggestion is to revamp the mini events (F1J power, F1H towline, and F1G Coupe) to make them less demanding technically and use these as the nontechnical counterparts to F1A, F1B, and F1C.
Free Flight: Duration
Last month I mentioned the instant-start and delayed prop release (DPR) systems that are almost standard equipment on today's Wakefield rubber models. They allow a one-handed launch without any wasted turns. At the Tom McLaughlan Memorial Contest in Pensacola last June, I had the chance to take a close look at John O'Dwyer's DPR-equipped Coupe. John's DPR system is a simple adaptation of the stock Winterhawk kit hub that John designed. Here's how it works: To keep the blades out in the "run" position at launch, John uses a simple wire latch attached to each blade. The free end of each wire is bent in an open loop, which hooks over a screw head added to the aluminum hub. The wires holds the blades with a slight sweepback. As soon as the blades start turning, centrifugal force pushes the blades straight out and the wires spring off the screws and out of the way. After the rubber motor runs down, the prop folds normally. (Most Wakefield-size DPR hubs use a much more complicated system that feathers the blades at launch for reduced drag and to eliminate the roll that pitched blades would introduce.)
Free Flight: Duration
WHY GO TO THE NATS? If you have never been to the National Aeromodeling Championships, or if your memory of the Nats experience of your youth has faded, let me suggest a few reasons to go: The photographs will, I hope, give you some of the flavor and scope of this particular contest. The event-by-event results, published elsewhere in this magazine, will fill in the details of winners and their scores. Now, for the reasons for you to start planning to attend the 1998 Nats: The Site: Located in Muncie, Indiana, the AMA's flying site is one of the best Free Flight fields in the East. Although it doesn't have the endless open space of Lost Hills, it is certainly adequate for Category III (two-minute maxes), even if the wind doesn't cooperate.
Free Flight: Duration
THE 1998 SYMPO: I hope that many of you have now seen the 1997 National Free Flight Society Symposium. Like all of the previous Sympos, it was a volunteer collaborative effort that we all can enjoy and share. Many thanks to those who participated as writers, artists, editors, or patrons. Now it's time to start to work on the 1998 Sympo, and NFFS needs your help. The 1998 Sympo editor, Dan Tracy, is soliciting proposals for technical articles. Send a brief description of the proposed article to Daniel Tracy, Box 244, Maple Valley WA 98038. Dan needs your proposal by January 15, 1998. If your proposal is accepted, the finished manuscript will be due no later than March 15, 1998.
Free Flight: Duration
A quick recap of the two main types of carbon fiber used for wing construction: woven cloth and unidirectional strip. Woven carbon cloth is similar to fiberglass cloth but is, of course, black in color. Unfortunately, the available weights and weaves of carbon fiber cloth are much more limited. Perhaps the most useful for Free Flight purposes is 2.9-ounce plain-weave cloth. Lighter carbon cloths are available, but they can be very, very expensive. Like fiberglass cloth, carbon-fiber cloth is limp and pliable; it is always used in combination with epoxy resin and a form to produce a rigid molded shell, such as a D-box. The cloth can be cut easily with sharp scissors. Unidirectional strip is a rigid sheet or strip of carbon fiber. Carbon-fiber strip is available, like balsa, in various thicknesses, widths, and lengths. Thicknesses range from .001-.060 inch. The thinner strips (.001-.003) are used primarily for rib capstrips. Thicker strips (.007-.042) are used for spar caps. The thickest strips (.030-.060) are used for trailing edges.
